AG burr finish

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That demonstration didn't tell me anything other than the magnitude of the forces going on. It explains and reinforces to me why I won't use crappy Moroso A/B epoxy in the intake tract because it always fails. Sorry to derail. J.Rob
 
That's a great video. I hate to say it....but it only reinforces the shortcomings of the carburetor. That's not to say EFI doesn't suffer from faults, also. My lowly Mazda 3 uses direct cylinder injection...maybe that's the answer.

Then again....the video illustrates how fuel can separate from (or perhaps more accurately never join) the air. The question becomes 'how much does it matter?'.

In a fuel economy race, I think it could be pretty detrimental. Same for a HP-per-pound of fuel race. But does that fuel have a net effect on HP? Not sure. The cylinders only care about the mixture they see, and how well they can burn it. The fuel stuck to the sides of the intake becomes a non-participant, to an extent.

In other words, if the air/fuel mixture that does make it to the cylinder is 'good' then the engine is gonna be happy. We see that in the impressive power and (generally) clean combustion.

It's safe to assume that fuel stuck to the intake walls eventually gets pulled back into the air, molecule by molecule, and into the cylinder. Is it well homogenized or not? The amount of turbulence we see would suggest that the fuel at least has a chance to be shaken and not stirred before it goes into the cylinder.

I agree on the epoxy comment above...no way would I use epoxy unless my back was against the wall.
 
Then again....the video illustrates how fuel can separate from (or perhaps more accurately never join) the air. The question becomes 'how much does it matter?'.
Very interesting nonetheless. Was quite cool to "see through" what would normally be an aluminum intake.
 
That's a great video. I hate to say it....but it only reinforces the shortcomings of the carburetor. That's not to say EFI doesn't suffer from faults, also. My lowly Mazda 3 uses direct cylinder injection...maybe that's the answer.

DI has many issues. It’s main attribute is fuel economy, which after 50k miles or something that starts going away because the DI stuff comes the valves when they retard the cam timing and the rest of the BS that CAFE standards cause.


Then again....the video illustrates how fuel can separate from (or perhaps more accurately never join) the air. The question becomes 'how much does it matter?'.

It’s a big deal.


In a fuel economy race, I think it could be pretty detrimental. Same for a HP-per-pound of fuel race. But does that fuel have a net effect on HP? Not sure. The cylinders only care about the mixture they see, and how well they can burn it. The fuel stuck to the sides of the intake becomes a non-participant, to an extent.

Fuel absolutely has a big effect on HP, and beyond that it doesn’t always show up on the dyno. If you have 2 engines making 500 HP at the same RPM and everything being equal, the engine with the lower BSFC will always be quicker and faster.

In other words, if the air/fuel mixture that does make it to the cylinder is 'good' then the engine is gonna be happy. We see that in the impressive power and (generally) clean combustion.

What happens to the fuel that isn’t mixed well with the air??? You can’t have impressive power and clean combustion running raw fuel into the chamber.


It's safe to assume that fuel stuck to the intake walls eventually gets pulled back into the air, molecule by molecule, and into the cylinder. Is it well homogenized or not? The amount of turbulence we see would suggest that the fuel at least has a chance to be shaken and not stirred before it goes into the cylinder.

It’s not safe to assume that fuel running down the walls eventually gets pulled back into the air. Once wet fuel is on a surface, it’s hard to get it back into the air. That’s why the burr finish has been on my mind for years. If you can get the rough finish to cause the fuel to break up into smaller sizes, you have a much better chance of getting the fuel back into the air and making the fuel useable to make power.

Warren Johnson said there is no such thing as a “dry” intake manifold and Darin Morgan said a rough surface finish from 3 inches above the injector to the valve so Morgan is saying essentially the same thing as WJ is.


I agree on the epoxy comment above...no way would I use epoxy unless my back was against the wall.
 
In other words, if the air/fuel mixture that does make it to the cylinder is 'good' then the engine is gonna be happy. We see that in the impressive power and (generally) clean combustion.

What happens to the fuel that isn’t mixed well with the air??? You can’t have impressive power and clean combustion running raw fuel into the chamber.

If that's true, then 99% of the hot rod engines out there aren't making impressive power/clean combustion...because we can see from the Kaase engine that even a high-end race engine has serious fuel separation issues. I bet that engine is making serious power despite the fuel issue. If the engine isn't running well...then Kaase is pulling our leg by showing what an unhealthy engine looks like. I don't think he's doing that.


It's safe to assume that fuel stuck to the intake walls eventually gets pulled back into the air, molecule by molecule, and into the cylinder. Is it well homogenized or not? The amount of turbulence we see would suggest that the fuel at least has a chance to be shaken and not stirred before it goes into the cylinder.

It’s not safe to assume that fuel running down the walls eventually gets pulled back into the air. Once wet fuel is on a surface, it’s hard to get it back into the air. That’s why the burr finish has been on my mind for years. If you can get the rough finish to cause the fuel to break up into smaller sizes, you have a much better chance of getting the fuel back into the air and making the fuel useable to make power.

The fuel must be getting pulled back into the air. If not, it would accumulate and the intake would eventually fill up with raw gas. The fuel has to be making its way into the chamber....and if it were running into the chamber in a purely liquid state, we wouldn't see clean spark plugs and good power. I think that if you are showing a decent A/F ratio on the exhaust side, the engine is fairly content. The compensation for the fuel puddling? The carb would be jetted leaner until the A/F ratio came into range. I'll bet that Kaase engine, despite the fuel puddling we see, is showing some decent BSFC numbers. I wish he told us.
 
LOL...I don’t want to quote all that.

I will say there are some very inefficient engines out there. There is a thread going on about this very thing. You have to burn fuel to make horsepower, not air. In fact, both Chris McGaha and Warren Johnson said after the Rev limit the Hemi was useless. It can’t burn as much fuel as a wedge, so it had to make that up with RPM. One could argue a PS engine is about as efficient as any NA engine out there, but the Hemi can’t burn fuel like a wedge. So it has to make it up with RPM. And IIRC, the EFI also killed the Hemi because NHRA mandated the intake manifold so hard that the Hemi couldn’t make up the short port length in the head with the runner length in the manifold. So...the inability to burn fuel, the RPM killing Rev limiter and the short runner length killed the Hemi in Pro Stock. I say it was the plan. In fact, one fairly prominent PS engine builder and I had some nasty emails between us about the Rev Limit and the fact that NHRA knew that it would kill the Hemi. He agreed that right there killed it, but he wouldn’t admit that NHRA knew it.

As far as making power, that engine Kaase HS on the dyno may have made a big number, but was it efficient? Without know the exact displacement, the BSAC, BSFC, A/F ratio and exact HP we will never know.

I do know that in about 1985 or 86, National Dragster had a tech article about someone putting a camera in the plenum of a very well tuned TR engine. In the article, they said that they had the camera in there, and if IIRC they had a light in there too. When the butterflies opened, the lights in the dyno room made it difficult to see what was going on. The upshot was they saw enough just at idle to make some changes and find some power. That was at IDLE.

The next issue was supposed to cover the testing and results with the dyno room lights off on a full pull. That never happened. Whoever was doing the test (I forget who it was) was no longer interested in showing that.

Several times I was going to do that very test, but with MFI I didn’t think it was worth it. I guess I should have put the nozzles in the plenum like I thought I should have and then did a video of that. But I never did either.

I can’t tell you how many times I’ve seen lean plugs and and rich exhaust ports. Many, many times. And the A/F meter said the tune was fine. That fuel blowing into the chamber stratifies and some of it does vaporize enough from the heat of combustion to be useable (all that excess fuel drops the chamber temp though...which isn’t good for power) and the rest of it burns, but it burns so late it does nothing for power. That’s why the A/F ratio looks ok.

Until I’m very close, I look at the plugs, the pistons and the exhaust port and until they a;l say the same thing, I don’t care what the A/F meter says.

We will see how the burr finish does as far as BSAC, BSFC, A/F ratio and horsepower in due time.
 
The fuel must be getting pulled back into the air. If not, it would accumulate and the intake would eventually fill up with raw gas. The fuel has to be making its way into the chamber....and if it were running into the chamber in a purely liquid state, we wouldn't see clean spark plugs and good power. I think that if you are showing a decent A/F ratio on the exhaust side, the engine is fairly content. The compensation for the fuel puddling? The carb would be jetted leaner until the A/F ratio came into range. I'll bet that Kaase engine, despite the fuel puddling we see, is showing some decent BSFC numbers. I wish he told us.

This might help: MegaSquirt-II X-Tau
 


I quickly read that, so I need to read it again, but I’m not so sure how the article assumes all the fuel from wall flow gets back to homogeneous. It may at steady state, but in transient situations I can’t see how thats even close to possible.

Any intake manifold/port is subject to the physics that occur regards of how the fuel gets there.

As MAP drops, the fuel that is atomized becomes liquid. That’s why you need an accelerator pump shot or the Xtau correction. How all that fuel becomes homogeneous again is escaping me. It may be burnable, but that occurs so late in the cycle that it doesn’t produce any power, or very little.

I need to read that again though. Slower this time.
 
I quickly read that, so I need to read it again, but I’m not so sure how the article assumes all the fuel from wall flow gets back to homogeneous. It may at steady state, but in transient situations I can’t see how thats even close to possible.

Any intake manifold/port is subject to the physics that occur regards of how the fuel gets there.

As MAP drops, the fuel that is atomized becomes liquid. That’s why you need an accelerator pump shot or the Xtau correction. How all that fuel becomes homogeneous again is escaping me. It may be burnable, but that occurs so late in the cycle that it doesn’t produce any power, or very little.

I need to read that again though. Slower this time.

Yeah, they are basically saying more fuel on throttle tip in and then when you get to a steady state, its being drawn from the walls so the EFI system in question will lean slightly as the fuel comes back into suspension. But it's also mentioning that it's kind of a re-occurring cycle of evaporation and fuel being deposited, which makes some sense given that the just added fuel is likely at least a little bit colder than the fuel that is on the walls in most cases. They then mention that this is a function of temperature and they compensate for that in the EFI systems. They also mention that the "tau" part of the x-tau can be several seconds if the engine is cold. So I would imagine this is fuel that gets burned in cycles following the one in which it became liquid and stuck to the walls. In this case, the roughness should help by allowing the air passing by near the boundary layer to exert more force on any fuel that is closest to the main air stream, basically shearing it from the walls. If totally smooth the boundary layer seems a little less likely to be disturbed.

I was thinking for a second about the MAP dropping but you're saying as the throttle opens so the vacuum goes away which would drop a vacuum gauge in the direction of zero - and I was thinking about kPa from the EFI tables where it would be an increasing number (101.325 kPa being no vacuum in standard temp and pressure, where idle would be 40-something kPa). Its the same thing, just taken from a different point of view.
 
In other words, if the air/fuel mixture that does make it to the cylinder is 'good' then the engine is gonna be happy. We see that in the impressive power and (generally) clean combustion.

What happens to the fuel that isn’t mixed well with the air??? You can’t have impressive power and clean combustion running raw fuel into the chamber.

If that's true, then 99% of the hot rod engines out there aren't making impressive power/clean combustion...because we can see from the Kaase engine that even a high-end race engine has serious fuel separation issues. I bet that engine is making serious power despite the fuel issue. If the engine isn't running well...then Kaase is pulling our leg by showing what an unhealthy engine looks like. I don't think he's doing that.


It's safe to assume that fuel stuck to the intake walls eventually gets pulled back into the air, molecule by molecule, and into the cylinder. Is it well homogenized or not? The amount of turbulence we see would suggest that the fuel at least has a chance to be shaken and not stirred before it goes into the cylinder.

It’s not safe to assume that fuel running down the walls eventually gets pulled back into the air. Once wet fuel is on a surface, it’s hard to get it back into the air. That’s why the burr finish has been on my mind for years. If you can get the rough finish to cause the fuel to break up into smaller sizes, you have a much better chance of getting the fuel back into the air and making the fuel useable to make power.

The fuel must be getting pulled back into the air. If not, it would accumulate and the intake would eventually fill up with raw gas. The fuel has to be making its way into the chamber....and if it were running into the chamber in a purely liquid state, we wouldn't see clean spark plugs and good power. I think that if you are showing a decent A/F ratio on the exhaust side, the engine is fairly content. The compensation for the fuel puddling? The carb would be jetted leaner until the A/F ratio came into range. I'll bet that Kaase engine, despite the fuel puddling we see, is showing some decent BSFC numbers. I wish he told us.

Having been exposed to J.Kaase and speaking with him several times--I doubt he is even capable of building an inefficient slug of an I.C.E. Why would he build a poor engine and then build a rig to stick his finger in a poor running engine? He wouldn't. I agree with you @gregcon here. Agree also on the fuel obviously getting reintroduced at some point into the cylinder otherwise eventually it would hydro lock the cylinder. Again though, I'm sure J.K. learned something from that experiment but I really didn't. I think we all tend to overthink a lot of this stuff. J.Rob
 
My trusty old 499" cuda with Dominator carb will leave a bit of smell on my clothes after I drive it. It did that with an 800DP as well, and basically every carbureted vehicle I've been in will do that. I think it's fair to say that's the result of unburned fuel....but I also think it's a low RPM, sitting in traffic issue. I don't think it would happen if I were only in the car at higher RPM.

I don't recall when/where but not too long ago I was looking at a video of a guy's engine.... he put a high quality camera into the intake and filmed it as he drive around town. I wish I could remember...but in any case it was a modern car that was Japanese. I think a Toyota inline 6 in a Supra.

When he would idle, you'd see some fuel swirling around. Not a lot of actual separation, but you could see the fuel in the air and that proved it wasn't well mixed. But as soon as he would hit the gas, it would pretty much vanish and while you could see turbulence from the camera shaking, you couldn't see any sort of fuel on the walls or in the air. It was actually kinda boring to watch.

I guess the point is...the Toyota 6 is probably far more 'friendly' than a nasty Kaase race engine. I don't think the kind of fuel puddling we see in the Kaase video happens on all engines all the time.
 
That demonstration didn't tell me anything other than the magnitude of the forces going on. It explains and reinforces to me why I won't use crappy Moroso A/B epoxy in the intake tract because it always fails. Sorry to derail. J.Rob

I had it in a pair on hot 406sbc (higly reworked holley alum. heads" , had no problems with it , street car , ran a best of 10.28 .
Gotta make a rough surface for best adhesion.
Have it in an intake manifold that I put a turtle in , just to smooth the edges of the turtle , ran it for a while , no problems with it either , course an intake doesn`t get as hot as heads do .
 
I would think the HC levels on a smog report and 02 sensor would give you a good idea on what is burning and what is not. Still a fan of port fuel injection close to the valve for 95% of us, not DI as the intake valves coat without the constant flow of atomized fuel across them.
 
A video explains alot. A picture being worth 1000 words.

reversion , pure and simple . How to stop "all" of it , is another matter , for people smarter than me .
All egines exibit it to some form of degree ...........jmo
 
Anyone willing to bet that the clear box window style intake probably had something to do with how much liquid fuel there was? It's not exactly a great 'manifold' shape.
 
I would think the HC levels on a smog report and 02 sensor would give you a good idea on what is burning and what is not. Still a fan of port fuel injection close to the valve for 95% of us, not DI as the intake valves coat without the constant flow of atomized fuel across them.


I agree, but even with the injector at the valve cover rail there is fuel up further in the intake.

I saw it with MFI and that’s why I started moving the injectors up. Had WJ and Morgan not said that it’s essentially the same with EFI I would have not guessed it.
 
Anyone willing to bet that the clear box window style intake probably had something to do with how much liquid fuel there was? It's not exactly a great 'manifold' shape.


It’s not, but I know other people hove put cameras in intakes and when they talk, they all say it’s like a hurricane in there. Burn alcohol and it’s at least twice as bad.
 
I don't think reversion is a fair term to use for what we see on the Kaase engine. Reversion implies air/fuel that is reversing direction on its way to the cylinder; what we see in the video is fuel that seem to never even be making it that far.

I think the video is very interesting and provides useful information, but I don't think it represents the average engine.
 
It’s not, but I know other people hove put cameras in intakes and when they talk, they all say it’s like a hurricane in there. Burn alcohol and it’s at least twice as bad.

I'm sure it's similar inside an actual manifold based on video research I've seen in ports and manifolds, but it seems to be to a lesser degree, maybe due to the texture of cast material.
 
As the rpm’s increase you can see the fuel on the plenum wall move farther up and farther into the plenum corners. It seems to me that is the beginning of reversion becoming a problem. The reverse pulses have built up enough to push the fuel up the plenum wall or there could be an increasing low pressure up there sucking the fuel up there. Pretty interesting video, not sure I would have put my finger in there!
 
About ready to send these...


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017E7A71-B026-439A-BE92-E838CEC21983.jpeg
 
You have 187 cc intake ports, 86 cc exhaust ports and the chambers are at 62 cc’s.

I should have measured them before I picked up the grinder but I crapped the bed on that one.

I don’t think your retainers fit your springs. Going to call TF in the AM and find out what s the issue.

Not coming over this weekend. Doc called and said our appointment is a video appointment. I have no clue why that is, as it was news to us, but I hate video appointments.
 
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